A film detailing an Australian music professor’s theory that Bach’s second wife Anna Magdalena composed one of his most famous works is causing a classical stir. Renowned cellist Steven Isserlis debunks the claim

Why are people so credulous when it comes to classical music? A film called Written by Mrs Bach has just appeared, followed by various breathless press reports, all seeming to give it credence. The film claims that Johann Sebastian Bach’s 6 Suites for solo cello, among the greatest, and most beloved, pieces of music ever written, were in fact composed by Bach’s second wife, Anna Magdalena. This “theory” was first propounded some years ago by Martin Jarvis, a professor at Charles Darwin University in Northern Territory, Australia, who is at the centre of this new film. The theory got some attention, was dismissed by Bach scholars and then (I thought) died forever; but here it is again.

Professor Jarvis is a charming and sincere man – I met him then to talk it over. But I’m afraid that his theory is pure rubbish. Anna Magdalena Bach did not write the Bach suites, any more than Anne Hathaway wrote Shakespeare’s plays, George Henry Lewes wrote George Eliot’s novels, or Freddie Starr ate his friend’s hamster.

Anna Magdalena copied out the Bach suites, in an error-ridden but invaluable manuscript, which may or may not be the earliest surviving source for the suites (Bach’s own copy, or copies, having been lost). The title page states clearly, in Anna Magdalena’s hand: 6 suites a Violoncello Solo senza basso composees par S(igno)r JS Bach.

Although I have not yet seen the film, I have seen the publicity materials for it, including the synopsis. The first sentence of this synopsis contains a howler – not a promising start: “Johann Sebastian Bach is recognised as the Father of Western Music.” Wrong - Bach is certainly not the father of western music; there were many great composers writing for a long time before he was born. The synopsis continues: “But most of his greatest works occurred after he met his second wife, Anna Magdalena Wilcke.” Big news. Johann Sebastian and Anna Magdalena married when Bach was in his mid-30s, some 30 years before he died; one would expect a composer to compose his greatest works during the second half of his life. And so on – how can anybody take this shoddy material seriously?

The main “evidence” for the theory seems to be the testimony of a handwriting expert, who has decided that Anna Magdalena’s copy shows that “the speed of the writing and the spacing between pen lifts were suggestive of composing rather than copying”. Why? Certainly to my eyes – and incidentally to those of the two musicians I know who were interviewed for the film, neither of whom believe the theory in any way – it is clearly a copy. There are no alterations or second thoughts, as there would be in a working manuscript.

Of course, it’s very possible that Anna Magdalena composed, though there’s really no evidence for it. She was obviously a very fine musician, who appeared often in concert as a singer with her husband at the keyboard. And there are many examples in history of women composers disguising their works under male names.

So why am I so sure that Bach himself composed the suites? It is partly because there are countless connections between the suites and many of his other works; but even more because the language is so clearly his – that perfection of utterance that is pure JS Bach.